Multiple hereditary exostoses (MHE;also known as hereditary multiple exostoses or multiple osteochondromas) is a genetic disorder characterized by the development of multiple bony protrusions and an assortment of variable non-skeletal symptoms. It is caused by mutations of either EXT1 or EXT2, which jointly encode a glycosyltransferase essential for heparan sulfate biosynthesis. This conference aims to promote the exchange of the most current information regarding MHE and the collaboration and synergy among laboratories studying this disease. This goal will be accomplished by bringing together world experts in the fields of orthopedics, human genetics, developmental biology, glycobiology, and related human bone diseases, and providing them with a highly focused forum to cultivate new ideas and cross-discipline collaborations. The conference will be held at the Four Points by Sheraton Boston Logan Airport hotel on October 29-Nov 1, 2009, and will have about 40 participants (including 24-28 invited speakers and 12-16 non-speaking discussants). There will be eight sessions focusing on clinical manifestation and orthopedics, human genetics, developmental biology of bone and cartilage (two sessions), biochemistry and enzymology of heparan sulfate, studies using conditional knockout mouse models, studies using non-mammalian model animals, and related bone diseases. Each session will have three to four speakers who will present 20-minute talks followed by 10 minutes of discussion. The format, roster, and size of the meeting are designed to maximize interactions among participants in an informal setting. Because of the extensive role of heparan sulfate in various morphogen signaling pathways, it is expected that the conference will have an impact beyond the scope of MHE and hopefully lead to a broader understanding of genetic disorders caused by abnormal morphogen signaling.